common definition of nouns

now let's consider the idea that it's possible to think of places as things (not too hard), and—though it may seem slightly disrespectful—it should be clear that people, in a broad sense, could be thought of as things as well.

slightly expanded definition of things

now for another small leap.
let's expand the notion of things to include events, actions, ideas, various phenomena, etc.
certainly this is not outside the realm of possibilities.
people talk about these sorts of...uh...things...all the time, just as they do about people, places, and all that we commonly refer to as things.

fully expanded definition of things

so, we see how the premise for this exhibition is quite plausible—that the world truly does consist of nothing but things.

as a little test, try now, with the expanded definition of things in mind, to think of anything that's not a thing. you can't.

so here's a working definition to consider: whatever can be defined, described, or somehow represented, is a thing.

keep this in mind as you go about your daily life.
remember how simple things really are.
don't get overly caught up in things.